Description

With these routines, the character ch is inserted before the character under the cursor. All characters to the right of the cursor are moved one space to the right, with the possibility of the rightmost character on the line being lost. The cursor position does not change
(after moving to y, x, if specified). (This does not imply use of the hardware insert character feature.)

Return Values

All routines return the integer ERR upon failure and an integer value other than ERR upon successful completion.